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    <title>Document</title>
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<script>
    //需求：foo([1,2,3],3) // [3,6,9]
    
    // function foo(arr,num){
    //     let newArr = [];
    //     for(let i = 0;i < arr.length;i++){
    //         newArr.push(arr[i] * num);
    //     }
    //     return newArr;
    // }

    // let result = foo([1,2,4],3);
    // console.log(result);


    //利用map()

    
    function foo(arr,num){
        return arr.map(e => e * num);
    }

    console.log(foo([1,2,3],3));



</script>
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